I apologize in advance as this post is a bit long winded but i have tried to incorporate anything that might be relevant to the point of probable repeating myself .
Hoping someone noticed the same phenomenon with AGM batteries compared to Flooded that would explain wha I am observing . I have just installed AGM batteries to replace the Flooded ones I have become accustom to for years
My system is small but very predictable and I can almost look it the log files and know very closely what they will show me but not with these AGM batteries everything seems to defy logic .
My output during the day is always about 40-60 amps in the day and 80-100 amps at night and it used to be that the following day my panels would input 110 -120 amps into the batteries by about 1pm then another 80-110 before the sun goes do wn around 6pm .
My batteries were good quality branded ones and I have looked back an the logs takes 4years ago at the same dates when they were new to compare to what im seeing now so I have a like for like comparison . Very little has changed until a month ago when I damaged a battery and felt it would be better to replace the whole bank with Trojan AGMs .
I am now noticing these AGM batteries accept around 40-60 amp/ Hrs by 11am and then reach the voltage set point which is the only 0.2 volts less than my Flooded ones were when they go from bulk to Adsorption which then reduces over the rest of the day so I get anything up to between 120-130 amp/hrs max . I can run things that use a lot of power to increase that while in Absorption but that seems counter productive .
My new battery bank is 400 amp hours compared to the flooded ones that were 600 amp hours but as im taking the same out of then only the DOD is different . Bulk is supposed to take the batteries up to around 80% SOC but I don't see how it can be . I am still using a Morningstar TS60 PMW charge controller that I find very accurate and trust , thats not changed .
I know AGM Batteries have less resistance so accept a charge easier which might explain why the voltages increase to the set point so much sooner but that appears to be a handicap not an advantage as stopping all the charge going into the batteries far to soon cant be achieving what is good charging practice of having Bulk not end until approx 80% charged .
I look at the voltage when we retire and turn off around 250 watts of consumption and watch voltage rise from about 24.5 to 25.75 and check in the morning and voltage has gone down slowly over the 8 hours to around 24.4 from the constant 65 Watts draw on things we cant turn off and al that seems acceptable but comparing the input to the consumption we are always short a few hundred watts and I have no reason to believe the TS60 or my Inverter is giving me false readings as I have tried various experiments to confirm there accuracy .
I would be so grateful if anyone could offer an explanation to put my mind at rest
Hoping someone noticed the same phenomenon with AGM batteries compared to Flooded that would explain wha I am observing . I have just installed AGM batteries to replace the Flooded ones I have become accustom to for years
My system is small but very predictable and I can almost look it the log files and know very closely what they will show me but not with these AGM batteries everything seems to defy logic .
My output during the day is always about 40-60 amps in the day and 80-100 amps at night and it used to be that the following day my panels would input 110 -120 amps into the batteries by about 1pm then another 80-110 before the sun goes do wn around 6pm .
My batteries were good quality branded ones and I have looked back an the logs takes 4years ago at the same dates when they were new to compare to what im seeing now so I have a like for like comparison . Very little has changed until a month ago when I damaged a battery and felt it would be better to replace the whole bank with Trojan AGMs .
I am now noticing these AGM batteries accept around 40-60 amp/ Hrs by 11am and then reach the voltage set point which is the only 0.2 volts less than my Flooded ones were when they go from bulk to Adsorption which then reduces over the rest of the day so I get anything up to between 120-130 amp/hrs max . I can run things that use a lot of power to increase that while in Absorption but that seems counter productive .
My new battery bank is 400 amp hours compared to the flooded ones that were 600 amp hours but as im taking the same out of then only the DOD is different . Bulk is supposed to take the batteries up to around 80% SOC but I don't see how it can be . I am still using a Morningstar TS60 PMW charge controller that I find very accurate and trust , thats not changed .
I know AGM Batteries have less resistance so accept a charge easier which might explain why the voltages increase to the set point so much sooner but that appears to be a handicap not an advantage as stopping all the charge going into the batteries far to soon cant be achieving what is good charging practice of having Bulk not end until approx 80% charged .
I look at the voltage when we retire and turn off around 250 watts of consumption and watch voltage rise from about 24.5 to 25.75 and check in the morning and voltage has gone down slowly over the 8 hours to around 24.4 from the constant 65 Watts draw on things we cant turn off and al that seems acceptable but comparing the input to the consumption we are always short a few hundred watts and I have no reason to believe the TS60 or my Inverter is giving me false readings as I have tried various experiments to confirm there accuracy .
I would be so grateful if anyone could offer an explanation to put my mind at rest
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